直接使用

- (void)viewDidLoad {
   [super viewDidLoad];
    NSString * text = @"测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字，测试文字";
    UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(10, 20, 200, 200)];
    label.numberOfLines = 0;
    label.backgroundColor = [UIColor greenColor];
    label.font = [UIFont boldSystemFontOfSize:16];
    label.lineBreakMode = NSLineBreakByCharWrapping;
    //设置字间距
    NSDictionary *dic = @{NSKernAttributeName:@10.f};
    NSMutableAttributedString * attributedString =     [[NSMutableAttributedString alloc] initWithString:text attributes:dic];
    NSMutableParagraphStyle * paragraphStyle = [[NSMutableParagraphStyle alloc]     init];
    [paragraphStyle setLineSpacing:30];//行间距
    [attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [text length])];
    [label setAttributedText:attributedString];
    [label sizeToFit];
    [self.view addSubview:label];
}

自定义一个 Category

#import <UIKit/UIKit.h>

@interface UILabel (ChangeLineSpaceAndWordSpace)
/**
 *  改变行间距
 */
+ (void)changeLineSpaceForLabel:(UILabel *)label WithSpace:(float)space;
/**
 *  改变字间距
 */
+ (void)changeWordSpaceForLabel:(UILabel *)label WithSpace:(float)space;
/**
 *  改变行间距和字间距
 */
+ (void)changeSpaceForLabel:(UILabel *)label withLineSpace:(float)lineSpace WordSpace:(float)wordSpace;
@end

#import "UILabel+ChangeLineSpaceAndWordSpace.h"

@implementation UILabel (ChangeLineSpaceAndWordSpace)
+ (void)changeLineSpaceForLabel:(UILabel *)label WithSpace:(float)space {
    NSString *labelText = label.text;
    NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:labelText];
    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    [paragraphStyle setLineSpacing:space];
    [attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [labelText length])];
    label.attributedText = attributedString;
    [label sizeToFit];
}

+ (void)changeWordSpaceForLabel:(UILabel *)label WithSpace:(float)space {
    NSString *labelText = label.text;
    NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:labelText attributes:@{NSKernAttributeName:@(space)}];
    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    [attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [labelText length])];
    label.attributedText = attributedString;
    [label sizeToFit];
}

+ (void)changeSpaceForLabel:(UILabel *)label withLineSpace:(float)lineSpace WordSpace:(float)wordSpace {
    NSString *labelText = label.text;
    NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:labelText attributes:@{NSKernAttributeName:@(wordSpace)}];
    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    [paragraphStyle setLineSpacing:lineSpace];
    [attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [labelText length])];
    label.attributedText = attributedString;
    [label sizeToFit];  
}
@end